The Indian Ocean Dipole Mode And Its Relationship With ENSO

The Indian Ocean dipole mode is one dominant pattern of interannual variability of the Indian Ocean. The generation mechanism of this mode is not well understood. Some hypotheses postulate that this mode is forced by ENSO, but others suggest that this mode results from the air-sea interactions of the Indian Ocean itself.

This study uses a coupled atmosphere-ocean general circulation model (CGCM) to investigate the relationship between the Indian Ocean Dipole mode and ENSO. Two CGCM simulations are performed. One includes both the Pacific and Indian Oceans in the model, and another includes only the Indian Ocean in the model. The spatial patterns and dominant timescales of the Indian Ocean dipole modes produced by these two simulations are compared.